sepal

English Thesaurus

1. one of the green parts that form the calyx of a flower (noun.plant)

hypernym	:	floral leaf,
definition	:	a modified leaf that is part of a flower (noun.plant)

part meronym	:	calyx,
definition	:	(botany) the whorl of sepals of a flower collectively forming the outer floral envelope or layer of the perianth enclosing and supporting the developing bud; usually green (noun.plant)